{{JULIANDAY|200|2|28}} pśinjaso 1794167 (proleptic) (last day of Julian leap year 200 AD, not leap in the proleptic Gregorian calendar)

{{JULIANDAY|200|3|1}} pśinjaso 1794168 (proleptic) (first day where the Julian and proleptic Gregorian calendars are equivalent)

{{JULIANDAY|300|2|28}} pśinjaso 1830691 (proleptic) (last day where the Julian and proleptic Gregorian calendars are equivalent)

{{JULIANDAY|300|3|1}} pśinjaso 1830692 (proleptic) (first day of difference between the Julian and proleptic Gregorian calendars, in leap Julian year 300 AD, not leap in the proleptic Gregorian calendar)

{{JULIANDAY|325|3|21}} pśinjaso 1839843 (proleptic) (spring equinox observed at the Christian First Council of Nicaea, taken as a reference for aligning the Julian calendar to the proleptic Gregorian)